Influence of adjuvants on the wettability and the control efficacy against Alternanthera philoxerordes of 20% fluroxypyr emulsifiable concentrate

The influence of adjuvants on the wettability and the efficacy of 20% fluroxypyr emulsifiable concentrate(EC) on Alternanthera philoxerordes was studied. The results showed that fluroxypyr mixed with silicone more significantly inhibited the growth and regenerative ability of A.philoxerordes than that mixed with azone or methyl oleate. The inhibitions of fresh weight of shoots and regenerative shoots of A.philoxerordes were 86.95% and 81.66%, respectively. The surface tension values and the contact angles of 20% fluroxypyr EC solutions were decreased significantly when azone, methyl oleate or organosilicone trisiloxane was added, but the leaf retentions were increased. After adding azone or organosilicone surfactants in herbicide solutions, the drying time were shorten except the case using methyl oleate. The wettabilities of herbicide solutions were improved after adding surfactants. There are some relationships between the change of physical characteristics and the enhancement effect of 20% fluroxypyr EC on A.philoxerordes.